Processed meats, sugary drinks linked to gut inflammation

The findings showed that intake of processed foods and animal-derived foods are associated with a higher relative volume of 'opportunistic' bacterial species, including certain bacteria belonging to Firmicutes and Ruminococcus sp -- all involved in pro-inflammatory activities. 

Eating plant-based foods such as nuts, fruit, vegetables, cereals, and oily fish and red wine was linked to a higher abundance of Faecalibacterium sp, which produce short chain fatty acids that help control inflammation and protect the integrity of the cells lining the gut. 

Similarly, intake of coffee was also associated with a higher relative abundance of Oscillibacter sp, while fermented dairy products, such as buttermilk and yoghurt were strongly associated with anti-inflammatory bacteria, such as Bifidobacterium, Lactobacillus, and Enterococcus sp. 

Food clusters of breads; legumes, such as lentils, peas, and chickpeas; fish; and nuts were consistently associated with a lower relative abundance of 'opportunistic' bacteria and pro-inflammatory activity. 

But a fast food cluster of meats, french fries, mayonnaise and soft drinks was associated with a cluster of 'unfriendly' Clostridium bolteae, Coprobacillus and Lachnospiraceae bacteria. 

In the absence of fibre, these bacteria turn to the mucus layer of the gut to feed off, leading to an erosion of the integrity of the gut, the researchers said, in the study published in the journal BMJ. 

"The findings suggest shared responses of the gut microbiota to the diet across patients with (Crohn's disease, ulcerative colitis, irritable bowel syndrome) and the general population that may be relevant to other disease contexts in which inflammation, gut microbial changes, and nutrition are a common thread," said Laura A. Bolte from the University of Groningen in the Netherlands. 

For the study, the team looked at the interplay between usual diet, gut microbes, and intestinal inflammation in 1,425 people with either inflammatory bowel disease (Crohn's disease or ulcerative colitis; 331); irritable bowel syndrome (223); or a normal gut (871).